Method for crimping crown caps



March 5, 1968 G. E. ROBERTS 3,371,463

METHOD FOR CRIMPING CROWN CAPS I Filed Feb. 4, 1965 Gsbkas E RbsaarsINVENTOR.

BY Q] ca I United States Patent 3,371,463 METHOD FOR CRIMPING CROWN CAPSGeorge E. Roberts, New York, N.Y., assignor to United States CrownCorporation, Saddle Brook, N.J., a corporation of Delaware Filed Feb. 4,1965, Ser. No. 430,379 2 Claims. (Cl. 53-42) ABSTRACT OF THE DISCLOSUREThere is disclosed a method of application of forces to crimp a crowncap and/ or a crown cap having an initially generally horizontallyradially extending tab. The method permits the positioning of the cap inany radially oriented position on the top of the neck of the containerto which it is to be crimped. There is simultaneously applied forces tothe top edge of the cap and to the top of its tab at points lying on aforce applying locus extending through the top edge application of forceposition on the cap and lying 45 to 60 degees from the vertical axisthrough the cap as measured in a direction below the tab and towards thecontainer axis. Continuing with the application of these forces whileapplying an inwardly directed radial force around the wall of the cap tobend it in while bending the tab downwardly and into an upwardly convexshape as viewed in cross section to fully crimp the wall into lockingengagement with the neck and further deform the tab downwardly andinwardly towards the container.

This invention relates to a method particularly well adapted to attach acrown cap with a radially projecting tab to the neck of a bottle.

In the bottling industry, it has long been known that a conventionalcrown cap may be provided with an integral tab which extends from thelower edge of its corrugated wall, to provide the necessary leverage forremoving the cap from a bottle without the aid of a separate opener. Theuse of this type of crown cap has produced its own variety of problems,especially in conjunction with the high speed equipment used to applycrowns in modern bottling plants. These machines use a die, eitherunitary or radially segmented, which comes down over the bottle neck tocrimp the cap onto the bottle. Obviously, these must be modified toaccommodate tabbed crown caps. Normally, the modification has involvedthe cutting away of a small portion of the die, or throat as it isusually called. This has not been altogether satisfactory since a throatso modified can be used only for the tabbed crown caps, and must bereplaced if the bottler resumes production with the usual untabbedcrowns. The down time of the bottling equipment has been an undesirableeffect of this. Also, the sealing characteristics of these dies were notalways reliable. If the tab of a cap were only slightly off-center fromthe cut-away portion of the throat, it would cant the cap on the bottleprior to the crimping of the corrugations, which prevented the propersealing of the cap.

Accordingly, it is an object of this invention to provide a method ofcrimping tabbed crown caps onto necks of bottles so that there is nounusual sensitivity to the precise radial location of the tab withrespect to the crimping throat, so that uniform and satisfactory sealingis assured.

Another object is to provide a method which will not limit the apparatusemployed only to use with tabbed crown caps; but rather the apparatuswill have the versatility of being usable for either regular crowns ortabbed crowns. This eliminates the need for equipment changeover andreduces the down time of the bottling equipment.

The present invention will be understood after reference to thefollowing description and the attached drawings wherein:

FIG. 1 is a sectional view of a crimping throat commencing to crimp thecorrugations of a tabbed crown to a bottle neck and to bend the tab intothe desired configuration;

FIG. 2 is a sectional view, similar to that of FIG. 1, showing therelative positions of the crimping throat and cap at the conclusion ofthe crimping operation;

FIG. 3 shows the crimping throat of FIGS. 1 and 2 used with aconventional crown cap without a tab; and

FIG. 4 shows the curvature of the tab, as seen along the line 4-4 inFIG. 2.

The environment of this invention is well known to those in the art andwill be described here only briefly. A horizontally moving supportingsurface is used to hold the bottles as the caps are applied. Above thenecks of the bottles is a platform with a slot for receiving the capsfrom a dispensing chute. The general type of platform may vary, but arepresentative example is shown in US. Patent 2,883,818 issued to MarionW. Gieskieng on Apr. 28, 1959. The platform, when holding the cap, isbodily lowered to deposit the cap on a bottle. Then, the crimping throatdescends over the cap and the bottle neck to secure the cap to thebottle. During this crimping operation, downward pressure is exerted onthe cap by means of a presser foot which extends through the bore of thecrimping throat.

The details of the crimping throat 2 used in this invention are shown inthe drawings. It is a generally toroidal body with a central bore 4. Amajor portion of the bore has a generally cylindrical wall 6 which maytaper slightly inwardly and upwardly, to the maximum angle of one degreeto the central axis of the bore. At the lower edge of the wall is arounded shoulder 8 which leads to a generally conical surface 10. Thissurface 10 is inclined to the central axis of the bore from 45 to 60degrees, in order to impart the curvature to the tab of a crown cap. Theaxial extent of this conical surface 10, indicated at a, isapproximately equal to the height of the cap wall after it is crimped.

The method of employing this crimping throat 2 to attach a crown cap toa bottle is shown sequentially in FIGS. 1 and 2. Initially, the surface10 contacts both the tab 12 and the outturned corrugations 14 of thecap, to evenly act on all sides of the cap and prevent disturbance ofits position on the neck 16 of the bottle. By virtue of the limiteddimension as, there is no unequal distribution of forces on the capwhich might tend to misorient it.

As the throat 2 descends, the smooth, inverted, generally conicalsurface bends the tab into its upwardly convex shape, shown in FIG. 4.Simultaneously, the wall 6 and shoulder 8 subject the upper portions ofthe cap wall at points of equal height and throughout its circumferenceto forces which bend the wall inwardly. This retains the cap in itscentralized location on the neck 16 of the bottle, and it provides for auniiform crimping action even in the area of the tab.

Continued advancement of the throat 2 will fully bend the cap wall intolocking engagement with the bottle neck and further deform the tab,until the throat reaches its final position shown in FIG. 2. The bottleis then withdrawn from the throat.

The utility of this method is, of course, restricted to those crownswhich have tabs of a significant width which permits them to be bentinto the shape shown in FIG. 4. Such tabs will extend at least 45degrees along the wall of their caps.

In reviewing the above-described method, it will be noted that there isnothing crucial about the radial relation of the tab to the crimpingdie. If the means which places the cap on the bottle locates it in anyangular position, the die is capable of properly crimping it in place.This was not the case in the prior art.

Since bottlers will often wish to crimp normal, untabbed crowns ontotheir bottles, the crimping die disclosed herein is also capable ofperforming that function. The ability to do this is shown in FIG. 3,where both the conical surface 10 and cylindrical surface 6 have causedthe corrugations to be bent inwardly.

In summary, it has been shown that the present invention presents a stepforward in the bottling art, inasmuch as it provides a method forreliably crimping a tabbed crown cap on a bottle and deforming its tab,without a great sensitivity to the location of the tab. Furthermore, theapparatus which performs this process is capable of performing equallywell known conventional crown caps which have no tabs.

It is realized that this invention may assume many forms other than thesingle one shown. Therefore, it is understood that the scope of thisinvention is not limited by the above description, but by the claimsWhich follow.

I claim:

1. The method of crimping a crown cap on the neck of a container, said'crown cap having a depending outwardly flared corrugated wall with aradially projecting corrugated upper surface tab that extends at least45 degrees along the wall of the cap in an initial horizontal attitude,comprising the steps of (a) placing the cap on the container neck;

(b) simultaneously applying forces throughout the whole top edge of thecap and to the top of its tab at points lying on a force applying locusextending through the top edge application of force position on the capand lying 45 to 60 degrees from the central axis through the cap asmeasured in a direction below the tab and towards the container axis;

5 (c) continuing the application of such forces while applying aninwardly directed radial force around the whole wall of 'said cap tobend in said wall while bending the tab downwardly and into an upwardlyconvex shape in cross section; and

(d) continuing the application of all these forces to fully crimp saidwall into locking engagement with said neck and further deform said tabdownwardly and inwardly towards the container.

2. The method of claim 1 wherein the area of extent of saidsimultaneously applied forces in step (b) is approximately equal to thearea of said cap wall after crimping.

References Cited FOREIGN PATENTS 3/1951 Italy. 7/ 1931 Germany.

TRAVIS s. MCGEHEE, Primary Examiner.

R. L. FARRIS, Examiner.

